A 100 ft run with one 4 ft gate
Open run, total fence line 100 ft, panel width (post spacing) 8 ft, gates 1 pcs, gate width 4 ft.
Posts needed
14 posts
- Panels to order (incl. 5% spare): 13
- Posts: 14
Fence Calculator
This fence calculator counts the panels and posts for a fence from its length, panel width and gates, for either an open run or a fully enclosed loop.
Last updated
How many panels and posts do I need for 100 ft of fence?
With 8 ft panels, 100 ft of fence needs 13 panels and 14 posts for an open run, because a run has one more post than it has sections. Add spare panels if you want a buffer.
Posts needed
14 posts
- Fence length excluding gates
- 96 ft
- Panels needed
- 12
- Panels to order (incl. 5% spare)
- 13
- PostsPanels + gates + 1 end post.
- 14
- Gates
- 1
Inputs
- Layout: Open run
- Total fence line: 100 ft
- Panel width (post spacing): 8 ft
- Gates: 1 pcs
- Gate width: 4 ft
- Spare panels: 5 %
- • Corners and gates usually need heavier posts. Check your fence system's requirements.
- • Setting posts in concrete? Choose Post holes in the concrete calculator.
- • Check property lines, permits and height limits with your local authority.
Results are estimates for planning only. Supplier specifications, product yields, site conditions and local codes vary. Confirm quantities with your supplier or a qualified professional before you buy or build.
How this is calculated
Formulas
- Panel run = total fence line − (gates × gate width).
- Panels = panel run ÷ panel width, rounded up.
- Sections = panels + gates.
- Posts = sections + 1 for an open run, or = sections for a closed loop.
- Panels to order = panels × (1 + spare %), rounded up.
Assumptions
- The fence is built from equal-width panels between posts, with gates sitting in the line.
- Panel width is measured from post centre to post centre.
- Rails, gravel boards, hardware, post concrete and fixings are not included. The calculator counts posts, not post lengths.
- Ground is treated as level. Slopes and steps may change how many panels you need.
Worked examples: common projects
A 40 m enclosed loop with two gates
Closed loop, total fence line 40 m, panel width (post spacing) 2.4 m, gates 2 pcs, gate width 1.2 m.
Posts needed
18 posts
- Panels to order (incl. 5% spare): 17
- Posts: 18
A 150 ft backyard run with two 4 ft gates
Open run, total fence line 150 ft, panel width (post spacing) 8 ft, gates 2 pcs, gate width 4 ft.
Posts needed
21 posts
- Panels to order (incl. 5% spare): 19
- Posts: 21
A 120 ft closed loop with one gate
Closed loop, total fence line 120 ft, panel width (post spacing) 8 ft, gates 1 pcs, gate width 4 ft.
Posts needed
16 posts
- Panels to order (incl. 5% spare): 16
- Posts: 16
Quick reference
Panels and posts by fence length
8 ft panels, an open run with no gates, 5% spare panels.
| Fence line | Panels | Panels to order | Posts |
|---|---|---|---|
| 50 ft | 7 | 8 | 8 |
| 100 ft | 13 | 14 | 14 |
| 150 ft | 19 | 20 | 20 |
| 200 ft | 25 | 27 | 26 |
| 300 ft | 38 | 40 | 39 |
Before you buy fencing
Measure the whole fence line, including gate openings. The calculator takes gates out of the length that needs panels, then counts the posts at the ends of every section, gates included.
Check boundary lines, permits and height limits with your local authority before you build. Corner, end and gate posts often need to be stronger than line posts, so check your fence system's guide. Setting posts in concrete? Estimate it with the concrete calculator, and plan gravel for drainage with the gravel calculator.
Planning around slopes, corners and posts
On sloping ground, fence panels are either stepped or racked to follow the slope, and the run you measure along the ground is longer than the horizontal distance. Measure along the fence line and check your panel system supports the slope you have.
Corner, end and gate posts carry more load than line posts, and they are usually larger or set deeper. A common rule of thumb is to set posts about a third of their length into the ground, and below the frost line where that applies. Confirm the requirements for your product and your area.
Frequently asked questions
How many posts do I need for a fence?
One more than the number of sections on an open run, where a section is a panel or a gate. A closed loop needs as many posts as sections.
Do gates need their own posts?
Yes. A gate sits between two posts, and the formula already counts them. Gate posts normally need to be heavier than line posts.
How far apart should fence posts be?
It depends on your panels. Panel fences are usually spaced to the panel width, commonly 6 to 8 feet (1.8–2.4 m). Follow your product's instructions.
How deep should fence posts go?
A common rule of thumb is about one third of the post's length, and below the frost line where that applies. Check local code.
How many posts for 100 ft of fence with 8 ft panels?
13 panels (100 ÷ 8, rounded up) and 14 posts for an open run, because posts are one more than the sections.
What if my fence has a corner?
Corners do not change the count. A corner is still a post between two sections. Add up the length of every side and enter the total.
How much concrete do I need per fence post?
Roughly 1.5 bags of 80 lb mix for a 10 inch wide, 24 inch deep hole around a 4 × 4 post. Use the Post holes option in the concrete calculator to enter your hole size, post width and number of posts.
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Results are estimates for planning only. Supplier specifications, product yields, site conditions and local codes vary. Confirm quantities with your supplier or a qualified professional before you buy or build.